Field of the Invention
Embodiments of the invention relate to a rolling sheet door system. More particularly, embodiments of the invention relate to an interlocking rolling sheet door system that forms a continuous curtain of corrugated panels, which can be assembled and disassembled by rolling the corrugated panels together and apart.
Description of the Related Art
Sheet door manufacturers currently manufacture rolling sheet doors in accordance with the American National Standards Institute/Door and Access Systems Manufacturers Association Standard 207 (ANSI/DASMA 207). In accordance with ANSI/DASMA 207, a “rolling sheet door” is a vertically operating, coiling door typically used in commercial, industrial, or self-storage applications with a curtain consisting of formed metal sheets seamed together.
ANSI/DASMA 207 defines a “curtain” as an assembly of curtain panels seamed together. A “curtain panel” is defined as a formed metal sheeting consisting of multiple corrugations with horizontal hems. A “hem” is defined as interlocking “hooks” on the top and bottom edge of the curtain panel used to create a seam. A “seam” is defined as a method for permanently interlocking two consecutive curtain panel hems for creating a continuous sheet door curtain.
A conventional rolling sheet door is shown in FIGS. 1(a), 1(b), and 1(c). As shown in FIG. 1(a), the conventional rolling sheet door 100 includes one or more curtain panels 110 and a hem 120 formed on each end of each curtain panel 110. As shown in FIG. 1(b), a joint 130 is formed between two consecutive engaging curtain panel hems 120. FIG. 1(c) shows a seamed joint 130 interlocking the two consecutive curtain panel hems 120 of the conventional rolling sheet door 100.
Current sheet door manufacturers use a “hem and seam”-type panel, also known as a “positive lock”-type panel, to assemble a curtain of interlockable curtain panels. One conventional process includes roll forming an upward hem and a downward hem, as shown in FIGS. 1(a), 1(b), and 1(c), overlapping the opposing hems 120, and then rolling an industrial style press over the two hems 120 to form a seamed joint 130, interlocking the two hems 120 together. This process has proven to be a trustworthy method and has been used in the sheet door industry for over 25 years to create interlocking rolling sheet doors.
Conventional rolling sheet doors formed using this process, however, are difficult to disassemble and maintenance in the field. Because the hems are seamed together, it is difficult to remove or replace a curtain panel, which may be damaged, without causing severe damage to both the astatic and structural stability of the rolling sheet door, thus making conventional rolling sheet doors of this type a “disposable door”.
For example, a curtain panel may be removed in the field by cutting the panel with a shear, snips, or a circular saw with the proper blade. The disadvantages of this process become apparent when trying to remove a curtain panel for repair, or add a new curtain panel. The new curtain panel would typically be attached by overlapping at least one rib of the corrugated curtain panel, and then using some type of fastener, such as a rivet or screw, to hold the curtain panels together. This process is not desirable when “curb appeal” is an area of concern. Overlapping the two curtain panels also adds weight to the door, which will have an adverse effect on the spring assembly, while also compromising the performance of the conventional rolling sheet door during, for example, a high wind event because of the added rigidity where the curtain panels overlap.
The curtain panel may also be removed in the field by manually opening the seam using a hammer, a flat head screw driver, a pry bar, or other tool to pry the two interlocked curtain panels apart. Once a portion of the hem is open, the claw end of the hammer or the pry bar is vigorously pulled across the door to open the rest of the seam. Due to the inconsistencies of pressure while pulling the tool across the door, such an action often results in the formation of ripples in the hems or other types of deformation. This process is not desirable when trying to add a new curtain panel. It is impossible to replicate the act of seaming in the field. In most cases, an operator attempts to seam the curtain panels using a hammer and “anvil” (e.g., another hammer, block of wood, heavy angle, etc.), and striking the hem across the length of the door. As a result, dents across the length of the door are routinely created. Forming a seam in the field between two interlocking hems is difficult because of the challenge in providing the proper amount of force or accuracy to form the seal. The major concern with both of these procedures is the effect they will have on rolling sheet door performance in certain conditions, such as high wind or impact resistance.
Another conventional rolling sheet door system includes a rolling steel or slat door, as shown in FIGS. 2(a), 2(b), and 2(c) (the “rolling slat door”). The rolling slat door is an overhead-coiling door having three basic components: a barrel assembly, guides, and a curtain. ANSI/DASMA 203-2004 defines a “barrel assembly” as a cylindrical horizontal member at the head of an opening that supports a door curtain and contains a counterbalance assembly. “Guides” are defined as a vertical assembly in which the door curtain travels and that is fastened to a jamb, retaining the edges of the door curtain and closing a space between a coil and a lintel. A “curtain” is defined as interlocked slats assembled together. ANSI/DASMA 203-2004 states that curtain slats shall interlock to allow the full range of angular rotation required to wrap the door curtain around the barrel assembly without binding or separation (i.e., the slats will not rotationally disengage). Due to the fact that the slats have to hinge or rotate around the barrel assembly (i.e., the hinge connecting adjacent slats is positioned on an interior side of the curtain door), the slats are limited to how they are assembled and disassembled. This limitation makes it difficult to repair the door curtain of slats in the field due to the amount of space needed to laterally slide slats apart and back together, as shown in FIG. 2(b).
What is needed is a rolling sheet door system that forms a continuous curtain of corrugated panels, which can be assembled and disassembled by rolling the corrugated panels together and apart without damage to the astatic or structural stability of the rolling sheet door.